Field of the Disclosure
This disclosure relates to mobility management in wireless networks and more particularly to mobility management using a multi-path transfer control protocol.
Description of the Related Art
Current long term evolution (LTE) networks maintain significant “state” information such as PDP Contexts, Bearers, access point names (APNs), General Packet Radio Services (GPRS) Tunnelling Protocol (GTP) tunnels, in network equipment. Most of the “states” are used to provide seamless mobility as devices move through coverage areas of the network. FIG. 1 illustrates a high level block diagram of an LTE network including cells 101, 102, 103, each with an enodeB to provide radio access. In addition to the RF portion of the network, the LTE network includes the evolved packet core (EPC) also shown in the high level block diagram of FIG. 1. The EPC includes the serving gateway (S-gateway) 107, the mobility management entity (MME) 106, the Home Subscriber Server (HSS) 108 and the packet data network (PDN) gateway 109. The HSS 108 provides information relating to subscribers. The PDN-gateway 109 is coupled to the packet network 115, which may be, e.g., the internet. The MME provides mobility management for the network including tracking location of device 104. The serving gateway communicates with the enodeB and acts as a local anchor for communications with the enodeB. More than one enodeB is typically served by the serving gateway. The PDN-gateway 109 acts as a gateway to packet networks such as the internet. The PDN-gateway 109 also assigns internet protocol (IP) addresses to the mobile devices and serves as an IP anchor. When a mobile device moves to a different serving gateway, the IP packets still flow through the PDN-gateway 109 (thus functioning as the anchor) and the same IP address is maintained using GTP-tunnel based approach to mobility management.
With the current GTP-tunnel based approach to mobility management, the PDN-gateway 109 acts as the anchor point and assigns the internet protocol (IP) address to the mobile device for use in the IP session while the mobile device is in the cell 101 served by the evolved nodeB. If the mobile device moves from coverage area 101 to another coverage area 102, the IP session is handed off to the new enodeB and the IP address assigned by the PDN gateway 109 is maintained in the new cell to maintain session continuity. There is significant amount of network equipment required to maintain the session continuity. Today's GTP tunnel based interface leads to a close bonding between the radio access network (RAN) and packet core network, which makes it very difficult to evolve separately and interwork with other radio access technologies (RATs) (e.g. Wireless local area network (LAN)). The approach was designed for backward compatibility and does not scale well with billions of emerging internet connected devices.
The current GTP tunnel based mobility management approach used in 4G-LTE networks does not scale effectively in fixture 5G networks with billions of emerging devices. Further, given many devices are stationary or occasionally mobile (and may not require session continuity while being mobile), current requirements to maintain significant state information become more difficult with the tremendous scaling expected of internet connected devices. Accordingly, a more effective approach for mobility management in future networks is desirable.